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(BQ) Part 2 book "Atlas of histopathology" presents the following contents: The male genital system, female reproductive system, breast, the endocrine system, the skin, bones, joints and soft tissues, skeletal muscles, central nervous system. | 8 199 The Male Genital System Ivan Damjanov Introduction The male reproductive system consists of testes excretory ducts such as the epididymis vas deferens parts of the lower urinary tract such as the urethra adnexal genital glands such as seminal vesicles and prostate and the penis. In this chapter we will deal primarily with the pathologic changes of the testis prostate and penis. Testis The testis is the male gonad whose principal functions are to produce sperm and synthesize male sexual hormones. Spermatogenesis takes place within the seminiferous tubules membrane bound hollow tubes containing germ cells in various stages of maturation and Sertoli cells Fig. 8.1 . The peritubular interstitial spaces contain Leydig cells the primary source of testosterone. The most important diseases of the testis are Developmental disorders Infections Neoplasms. Developmental Disorders The normal development of the testis begins with the formation of genital fold on the posterior side of the fetal abdominal coelomic cavity. Once formed the testes slowly descend through the inguinal canal into the scrotum which they reach during the last stages of pregnancy. Incomplete descent of the testes into their normal scrotal position is called cryptorchidism. Bilateral cryptorchidism may cause infertility. Cryptorchidism is also a risk factor for germ cell tumors. Cryptorchid testes surgically positioned into the scrotum during early childhood develop normally and usually do not differ from normal testes. If the cryptorchid testes are left in the abnormal position they will show variable signs of atrophy of seminal epithelium and incomplete or arrested spermatogenesis. The basement membranes of the seminiferous tubules become thickened and there is interstitial fibrosis Figs 8.2A and B . Sertoli-only syndrome is a term used to describe a group of infertile patients who have genetic azoospermia. Testicular biopsy will typically reveal a lack of germ cells in the seminiferous tubules .